Factory tach wiring

If I wasn't attempting to correctly clone OEM, I would buy a pair of Packard 56 terminals for the bulkhead connector and route this wire through the one of those unused ports. And of course male/female disconnect terminals just outside the firewall ( something very different in fitment from the fusible link connector ). This so the tack wire could be separated from the "wiper"/bulkhead connector. That is what they did with the 3 wire loom coming from neutral safety switch of automatic trans after all.
So my tach wiring would appear "standardized" instead of "add on" of 1 of the 3 possible instruments in this panels center pod.
The firewall hole and grommet method,,, that's for the performance indicators vacuum line.